1. Field of the Invention
This invention involves a power loader lifting apparatus in general, and, more specifically, a front-end loader bucket implement equipped with a hydraulically-powered lift apparatus for lifting, gripping and carrying loads too wide for the loader bucket.
2. Description of the Related Art
The "front-end loader" is well-known in the art. This is a powered vehicle equipped with at least one hydraulically-powered arm adapted for the attachment of a range of implements. Such implements include powered tools such as earth augers, power chisels, claw-like grippers, and shovels. Other common implements include unpowered devices such as simple lifts, buckets, rakes, and a variety of blades.
Perhaps because of the wide range of implements known in the art, the front-end loader operator is often faced with the task of removing one implement and replacing it with another during the course of his work. For instance, the typical loader buckets used in the loading of earth-hauling equipment with sand, gravel and landfill are not suited for handing nonparticulate materials. The loader operator is obliged to remove the loader bucket and attach a lift fork or a powered gripper when her task shifts from loading particulate materials to unloading pallets or bales. This inconvenience and inefficiency is well-known in the art and has motivated a number of practitioners to develop improvements to the standard implements.
The intent of many such implement improvements is to increase the efficiency of the front-end loader operation by reducing or eliminating the time required to change implements during the job. Several implements are known for use as temporary attachments to a loader bucket. These usually are fork lift attachments adapted for rapid mounting on a loader bucket. Some may require a special supporting structure on the bottom of the loader bucket. Most such add-on fork lifts are designed to effectively extend the bucket bottom to form a lift platform at the front edge of the bucket. This extended-bucket lift is then powered by the front-end loader arm in the normal manner. The bucket is normally rendered useless when the lift attachment is in place.
In U.S. Pat. No. 3,706,388, Westendorf discloses a fork attachment for a loader bucket that is quickly and easily attached to the loader bucket to permit the loader bucket to be used as a loader fork. Westendorf's design requires the interior of the loader bucket to remain clear of material and limits the fork lift load width to the width of the loader bucket.
In U.S. Pat. No. 4,125,952, Jennings discloses an attachment fork for power-operated buckets that is designed to cantilever from the leading edge of the bucket. Jennings accomplishes this by providing hinge components for attachment to the back wall of the bucket, which serve to ensure a secure and rigid attachment without weakening the bucket structure. Jennings' invention is unsuited for lifting loads having widths wider than the bucket width.
In U.S. Pat. No. 4,242,035, Hornstein discloses apparatus for converting a curved scoop-type loader bucket to a pallet loader through attachment of two identical tine harnesses. Hornstein merely clamps two tines to the loader bucket with chains, thereby adding a fork extension to the bottom of the loader bucket. His means for attachment prevents use of the loader bucket while the fork tines are attached.
In U.S. Pat. No. 4,422,819, Guest discloses a fold-away fork lift attachment for loader buckets. Guest's invention is designed for permanent attachment to the upper inner wall of the loader bucket. When the loader bucket is in use, the two fork tines are folded up against the inner upper wall of the loader bucket. When the two forks are folded down for use as a fork lift, the loader bucket is blocked and not usable.
In U.S. Pat. No. 4,545,721, Pettersson discloses a device having both a loader bucket and a fork lift. Pettersson's loader bucket is hinged and rests on the fork lift during use as a loader bucket. When Pettersson's invention is used as a fork lift, the loader bucket portion is tilted back by independent hydraulically-powered means, thereby exposing the fork lift on which the bucket normally rests. Pettersson's invention does not permit the simultaneous use of both bucket and lifting fork.
In U.S. Pat. No. 4,565,485, Willman discloses a mechanical grab and scoop combination for use with a front-end loader that overcomes the normal requirement for two separate devices for grasping and scooping operations. Willman's invention consists of upper and lower toothed grab elements that form a scoop bucket when fully closed together. When these two elements are fully separated, the lower grab element can serve as an awkward fork lift. Willman's invention does not permit the simultaneous use of a bucket and fork lift.
The wide range of front-end loader implements known in the art attests to the widely- and strongly-felt need for implements leading to efficient loader operation through multiple functionality. Most of the implements known in the art require the loader operator to change implements, add attachments, or switch configurations when changing the job function. Three common front-end loader functions are the lift fork function, the loader bucket function, and the grabber function. There is a need for a front-end loader implement offering all three such functions simultaneously without functional limitations imposed by such a combination. Although such simultaneous functionality can be provided with three different vehicles, until now, such a combination in a single loader implement has been unknown in the art. These unresolved problems and deficiencies are clearly felt in the art and are solved in the present invention in the manner described below.